The present disclosure relates to an active grille and more particularly, to reversibly opening and closing blades of the grille using active materials. To effect opening and closing, the active materials are in operative communication with the blades that define the grille or form at least a portion of the blade. The active materials change at least one attribute in response to an activation signal to effect repositioning of the blades.
Airflow through a vehicle can affect many aspects of vehicle performance including vehicle drag, cooling/heat exchange for a vehicle powertrain, air conditioning systems, brakes, and the like. Reductions in vehicle drag improve fuel economy. As used herein, the term “airflow” refers to the motion of air through parts of a vehicle relative to the exterior surface of the vehicle or surfaces of elements of the vehicle along which exterior airflow can be directed such as surfaces in the engine compartment. The term “drag” refers to the resistance caused by friction in a direction opposite that of the motion of the center of gravity for a moving body in a fluid. Vehicle grilles in the art of vehicle manufacture are generally comprised of blades of a predetermined, non-adjustable geometry, location, orientation, and stiffness. Such devices generally do not adapt as driving conditions change, thus the airflow through the grille cannot be adjusted to better suit the changing driving conditions.
Accordingly, there exists a need for an adjustable exterior vehicle grille for controlling fluid flow under varying conditions such as, for example, an adjustable exterior vehicle grille for controlling airflow through the grille under varying driving conditions.